DE102012103749A1 - Reactor comprises heatable housing, whose upper region has heating surface and is transversed through rotor, where wiper elements are provided for distribution of liquid product on heating surface which has collection and discharge area - Google Patents

Abstract

Reactor (1) comprises a heatable housing (2), whose upper region has a heating surface (3) and is transversed through a rotor (6) in inner side, where the wiper elements (4) are provided for distribution of liquid product on the heating surface. The heating surface within the housing has the collection area and a discharge area for the product. The rotor extends into the collection area and has stirring elements disposed in the collection area for mixing the product. An independent claim is also included for operating a reactor comprising increasing residence time within the reactor housing when the product is highly accumulated, and continuously rotating the rotor.

Description

The invention relates to a reactor with a heatable housing according to the features in the preamble of patent claim 1 and a method for operating such a reactor.

From the WO 2011/131793 A2 a device for the depolymerization of hydrocarbonaceous products is known. The reactor used is charged with a liquid product which comes into contact with a heating surface. When the product has become hot enough and at a temperature that is long enough, portions of the long-chain hydrocarbon molecules will break down into shorter-chain hydrocarbon molecules: the entire region where the product has sufficiently high temperature to break down into short molecular chains is the reaction region. The short-chain molecules are evaporated. The feed product is introduced at an upper end of the reactor and distributed by a rotating wiper system evenly on the inner circumference of the reactor, ie on the heating surface. The product flows as a film due to gravity at the externally heated heating surface down. In order to ensure a uniform wetting of the heating surface, an intensive mixing and high turbulence in the product film is produced. This achieves a cleaning of the heating wall and increases the heat transfer performance. The choice of the wiper system is largely determined by the product properties such as viscosity, the evaporation ratios and the ratio of the feed amount to the residue amount and the criteria such as the permissibility of abrasion, abrasion and corrosion.

Conventional wiper systems have an externally driven rotor with integrated wiper elements. The wiper elements can be radially freely movable and be pressed against the heating surface by centrifugal forces during the rotation outwards, so that there is a mechanical action of the wiper elements on the product film.

For hydrocarbons, which are to be cleaved to shorter molecular chains and then evaporated, the remaining hydrocarbons are getting thicker and more viscous. Strong clinging forms with a tarry consistency. The adhesions of the product become more intense with increasing evaporation of the short molecular chains, i. H. with increasing residence time of the product in the reactor, towards the bottom more and more solid and viscous. The surfaces of the reactor inside are therefore subject to different thermal loads in a wide range and exposed to different contaminants. Therefore, a rotor with consistent design over its length neither guarantee optimal heat input on the entire heating surface nor achieve an optimum cleaning result on the heating surface. In addition, non-heating areas such as the collection area and the concentrate discharge area are also causing problems in the same sense. Long residence times of the product generally lead to a higher molecular splitting rate. In order to achieve the desired product quality, a targeted residence time in combination with a specific product temperature is necessary. The objectives, a specifically adjustable residence time in combination with the most uniform possible temperature distribution in the product and at the same time good cleaning of the heating surfaces, the collecting area and the discharge area are unfortunately contradictory.

• a) eine gleichmäßige Benetzung der Heizfläche zu gewährleisten,
• b) das Produkt auf der Heizfläche und im Konzentratsammelbereich intensiv zu durchmischen,
• c) eine gezielt einstellbar Verweilzeit innerhalb des Reaktors zu realisieren.

The invention is therefore based on the object to show a reactor which fulfills various requirements simultaneously:

• a) ensure uniform wetting of the heating surface,
• b) intensively mixing the product on the heating surface and in the concentrate collecting area,
• c) to realize a specifically adjustable residence time within the reactor.

Furthermore, the invention has the object to provide a method for operating a reactor with these properties, with which in particular a specifically adjustable residence time can be better achieved.

The objective part of this object is achieved in a reactor having the features of patent claim 1.

The inventive method is the subject of claim 12.

Advantageous developments of the invention are the subject of the respective subclaims.

The reactor according to the invention has a heatable housing whose upper region has a heating surface on the inside. The housing is internally penetrated by a single rotor whose wiper elements serve to distribute a liquid product on the heating surface. The liquid product flows down by gravity. Below the upper range, d. H. Below the heating surfaces is a collection area for the product. At the end sits the discharge area for the concentrate.

The special feature of the reactor according to the invention is that the rotor extends into the collecting area and preferably into the discharge area. Stirring elements arranged in the collecting area, which are connected to the rotor, provide for Mixing the concentrate of the product in the collecting area and keeping it clean and support the discharge of the concentrate.

Consequently, the rotor according to the invention not only has the function of driving the wiper elements for distributing the product on the heating surface, but to a certain extent also has an agitator which serves for thorough mixing of the concentrate in the collecting area.

However, the agitator not only has the function of passing through the residues of the product, but also the function of finally discharging the product from the reactor. The stirring elements can therefore be considered at least partially as components of a discharge system. The rotor thus has the function of a conveyor in the lower area, while in the upper area it primarily serves for thorough mixing and distribution of the product. Both in the upper and in the lower area of the rotor serves with its wiper and conveyor elements for cleaning the heating surfaces and the collection and discharge area.

Ensuring the very good mixing and generation of high product turbulence ensures a uniform temperature distribution in the product.

The invention has the advantage that with a single rotor, several process-relevant requirements for distribution or transport of the product can be achieved, namely in adaptation to the respective local properties of the product, in particular its local viscosity. While the system of wiper elements and stirring elements represents the basic configuration of the rotor according to the invention, it is quite possible within the scope of the invention to make a further adaptation to the product to be processed.

• a) gleichmäßige Benetzung der Heizfläche,
• b) das Produkt wird auf der Heizfläche und im Konzentratsammelbereich intensiv durchmischt,
• c) die Temperatur wird für alle Produktbereiche möglichst gleichgehalten,
• d) die Heizfläche, der Sammelbereich und der Austragsbereich werden sauber und betriebsfähig gehalten,
• e) es wird eine gezielt einstellbare Verweilzeit innerhalb des Reaktors realisiert,
• f) der Austrag des Konzentrates wird sichergestellt.

The invention therefore simultaneously fulfills the following tasks:

• a) uniform wetting of the heating surface,
• b) the product is thoroughly mixed on the heating surface and in the concentrate collecting area,
• c) the temperature is kept as constant as possible for all product areas,
• d) the heating surface, the collection area and the discharge area are kept clean and operational,
• e) a specifically settable residence time is achieved within the reactor,
• f) the discharge of the concentrate is ensured.

In particular, the rotor can have at least two different wiper elements in succession in the longitudinal direction of its rotor axis. In an upper part of the rotor, it is known to use wiper elements which, as in the prior art, are suitable for unproblematic products or their distribution on the heating surface. In the subsequent central region of the rotor, the configuration of the wiper elements can be deviating, in particular adapted to increasing viscous liquids. Finally, the lower region of the rotor, in which the stirring elements are arranged, follows. All areas of the rotor rotate at the same speed and are connected to the centrally driven shaft.

In the upper region of the rotor, the wiper elements are preferably designed as a valve following the rotation of the rotor, which exerts a contact pressure force on the heating surface. Such a flap may be in operative engagement with the product film on the heating surface by centrifugal force, i. H. durchst him and distribute and ablate. The higher the weight of the flap, the greater the centrifugal force and thus the pressure exerted on the product film. Of course, it is possible within the scope of the invention to provide wiper elements of different configuration even in a single longitudinal section or height range of the rotor, d. H. in particular trailing flaps with different weights.

In particular, a fixed wiper element may be provided in the subsequent central longitudinal section of the rotor. The distance of the wiper element from the heating surface may be selected depending on the product.

In the lower part of the reactor, d. H. the collection area in which the stirring elements are effective, less the interaction with the housing wall of importance, rather than that the concentrate is mixed, thereby promoting concentrate from bottom to top, so that this again comes into contact with the reaction space, to be able to extract even more short molecule chains from the concentrate.

For this purpose, the stirring elements can be set at an angle which causes a displacement of the reaction mixture transversely to the direction of movement of the concentrate. The stirring elements can be arranged, for example helically, for this purpose.

The collecting area, for example, tapers conically downwards, so that the concentrate is fed to a bottom, arranged central line as an output. The stirring elements can be adapted to this conically tapered inner contour of the collecting region, ie, they are also arranged conically tapering. The scope of the rotor decreases in this case to the lower end of the collection area.

Another essential aspect of the invention is to specifically influence the residence time of the product within the reactor, at the same time to improve the intensive mixing and finally to ensure the degradation of encrustations on the heating surface.

The residence time influences the achievable quality of the product produced. In the upper area, it is relatively short and little to influence. A higher residence time can be realized by increasing the volume of the reactor. According to the invention, it is provided that the volume adjacent to the lower collecting area is increased. Below the heating surface can therefore be provided a cylindrical extension.

This allows the reactor to expose product to process conditions over a longer period of time. It is important that the rotor system according to the invention is also effective in the additional reactor volume and brings about a good mixing, a return to the upper region of the reactor and a cleaning of the walls. Depending on the need for this, the collecting area and / or the cylindrical extension are heated.

Alternatively, it is possible to provide not only a physical extension of the reactor, but to increase the residence volume by accumulating the product, so to speak, so that the height level of the product is raised. In this additional residence volume acts on the same rotor, as described above, at least one stirring element. Stirring elements can be made upwards or downwards as described above, in order to allow improved mixing of the accumulated volume. In addition, mixing reduces the risk of products settling on the wall of the housing and forming product encrustations.

In principle, in addition to the increased residence time volume, it may be provided to form the wiper elements in the different rotor zones in a recirculating manner, so that the product is at least partially prevented from flowing down due to gravity.

The reactor is suitable by the choice of wiper elements for very large viscosity ranges, whereby high product yields are possible. An improvement in the recycling of valuable materials in the process also means an improvement in the efficiency.

With the invention, a uniform and definable Verweilsspektrum combined with a targeted and uniform temperature distribution for the product allows. Due to the uniform temperature control, it is only possible to set controlled, defined product qualities. The very good, over long time maintained heat transfer also allows lower heating medium temperatures, which is equivalent to an energy saving. This improves the energy efficiency of the process. The continuous operation without manual intervention also allows high levels of efficiency in production. The fewer human intervention in the process, the more secure the process is for operators and maintenance personnel. The reactor according to the invention is characterized by large time intervals for maintenance and cleaning work on the apparatus.

As the product to be processed hydrocarbon-containing products are used, in particular waste oil or plastic melt.

The invention will be explained in more detail with reference to the embodiments illustrated in the drawings. Show it:

1 a schematic representation of a first embodiment of a reactor in longitudinal section;

2 a schematic representation of a second embodiment of a reactor in longitudinal section;

3a in cross section and in a perspective view of a first and b embodiment of a wiper element;

4a in cross-section and in a perspective view of a second and b embodiment of a wiper element;

5a in cross section and in a perspective view of third and b embodiments of a wiper element;

6 in a perspective view another embodiment of a reactor and

7 in a schematic representation of another embodiment of a

Reactor in longitudinal section

1 shows a reactor 1 with a housing 2 in cylindrical design. The longitudinal axis of the housing 2 stands vertically. The housing 2 is heated from the outside. An upper area H of the housing 2 forms the heating zone. In this area H is the housing wall 2 double-walled, wherein in the space as a heating means steam or liquid is passed. An electric heating is possible. The heat gets inside the case 2 a heating surface 3 created.

In the reactor 1 is introduced from above a product P in a manner not shown. The product P should be on the heating surface 3 be distributed. This is done by means of wiper elements 4 . 5 a rotor 6 , The rotor 6 penetrates the housing 1 longitudinal. The rotor axis R corresponds to the central longitudinal axis of the cylindrical housing 2 ,

The rotor 6 has in this embodiment first wiper elements 4 and second wiper elements 5 in successive lengths of the rotor 6 are arranged. The configuration of the wiper elements 4 . 5 is different. The wiper elements 4 . 5 however, they are moving at the same speed.

In a lower area of the reactor 1 Collects the product P. There, the rotor extends 6 , The rotor shaft 7 of the rotor 6 drives here arranged stirring elements 8th on, which can also be referred to as Austragelemente. This area is conical and is used as a collection area 9 designated.

Product discharge takes place at the lower end in a discharge area 9b , The lower part of the rotor R, ie the portion which is in the region of the conical collection area 9 is in this embodiment has several arms 10 arranged paddles 12 attached to the taper of the collection area 9 are adjusted and near the wall of the housing 2 are arranged. The individual paddles 10 are set at an angle so that they as a discharge element the product P in the direction of the bottom outlet 11 promote. At the same time, the paddles work 12 a mixing of the product P in the collection area 9 , As an alternative to carrying out paddles on arms, paddles without arms can also be used. The collection area 9 can be optionally heated in this, as well as in the following embodiments.

The embodiment of the 2 is different from the one of 1 in that, below the upper region H of the reactor 1a, a collecting region formed as a buffer container 9a is arranged. The collection area 9a is much larger in volume than the conical collecting area 9 in 1 , Also for this embodiment it is provided that a schematically illustrated stirring element 8th the product P in the collection area 9a permanently mixed to the efficiency of the reactor 1a to increase. About a pump 13 The product P or the condensate of the product P can be discharged from the reactor Ia. Incidentally, the explanation of the 1 Referenced. Substantially identical components were used with the in 1 introduced reference numerals. This also applies to the other illustrations.

The much larger collection container 9a allows the residence time of the product P within the reactor 1a significantly increase.

The 3 shows a cross section through a rotor 6 in an upper altitude range. The rotor 6 has several wiper elements 14 . 15 attached to a retaining ring 16 are attached. The retaining ring 16 is about striving 17 with the rotor shaft 7 connected. At the wiper elements 14 . 15 These are trailing flaps that rotate on the retaining ring 16 are attached. The left wiper element in the image plane 14 has a greater weight than the right wiper element in the image plane 15 , As a result, the wiper element exercises 14 a greater force on the heating surface 3 of the housing 2 Applied product on or is directly with the heating surface 3 in contact. The other wiper element 15 is lighter and thus experiences lower centrifugal forces at constant speed. The effect on the product on the heating surface 3 is lower. The arrow P1 shows the direction of rotation of the rotor 6 ,

3b shows a perspective view of the wiper element 15 holding rings 16 is mounted rotatably. The wiper element 15 is configured in this embodiment in cross section L-shaped.

4 shows another embodiment of a wiper element. At the wiper element 18 it is a radial of the rotor shaft 7 protruding paddle that extends parallel to the rotor axis R. 4b shows the wiper element 18 in perspective view. In this embodiment, there are four identically configured wiper elements 18 provided to the heating surface 3 of the housing 2 are equally spaced and a gap S to the housing 2 set free. Such wiper elements 18 are suitable for in the 1 and 2 illustrated central region of the rotor 6 ie, where the viscosity of the product is already increasing due to increasing evaporation.

5a finally shows a possible embodiment of a stirring element 19 , Unlike the wiper element 18 of the 4 is the stirring element 19 is not arranged parallel to the rotor axis R, but is employed at an angle to the rotor axis R. Due to this employment, the viscous product is deflected and diverted up or down depending on the orientation of the angle of attack.

From the perspective view of 5b it can be seen that the stirring elements 19 . 20 may also be provided with opposing angles employed, so that the product of the upper in the image plane stirring element 20 downwards in the direction of the arrow P2 and from the bottom stirring element in the image plane 19 in the direction of arrow P3 is conveyed upward. This results in intensive mixing of the product in the collection area 9 causes.

6 shows an embodiment of a reactor 1b in which between the upper region H, which is designed as a heating region and that at the lower end of the reactor 1b trained tapered collection area 9 a storage area 23 is trained. The storage area 23 creates a certain additional volume, which may be referred to as the residence time volume for the product P. The product P is raised to a higher level N, so that the level N is above the collection area 9 In addition, it rises to just below the upper heated area H of the reactor 1b , The rotor 6 according to the invention, it also penetrates the storage area 23 and extends into the collection area 9 , In the storage area 23 are as well as in the collection area 9 additional stirring elements 21 intended. It can be seen that the stirring elements 21 paddles located at outer ends of struts 22 possess, which have different angles of attack and are thus oriented differently. Alternatively to a design of paddles on struts and paddles without struts can be used. In addition, the paddles can 22 also be pivoted about a second spatial axis, so that the mixing of the product by means of the divergent stirring elements 21 becomes even more intense. In each case a radial plane of the rotor are stirring elements 21 in a constant configuration. The configuration of the stirring elements 21 adjacent radial planes deviate from each other.

7 shows an alternative embodiment of a reactor 1c , Just as in the embodiment of 6 also has this reactor 1c an upper area H, which may be referred to as a heating zone and is provided with a corresponding heating device. At this upper area H, the collection area closes 9 in conical configuration, as it is already in 1 has been shown. Again, there are stirring elements 8th as well as wiper elements 4 present, however, which are shown only schematically. The particular feature of this embodiment is that the level N up to which the product P enters the reactor 1c has been introduced, compared to the embodiment of the 1 and 1b has been raised. The level N or the storage area protrudes into the upper area H, as a result of which the residence time volume increases considerably. By this damming of the product P is in the same manner as in the embodiment of the 6 the residence time volume increased significantly. The configuration of the wiper elements is adapted to the level. In this lower area, there are therefore wiper elements, which are near the heating surface 3 are arranged and stirring elements.

LIST OF REFERENCE NUMBERS

1

reactor housing

1a

reactor housing

1b

reactor housing

1c

reactor housing

2

heating surface

3

heating surface

4

wiper member

5

wiper member

6

rotor

7

rotor shaft

8th

stirrer

9

collecting area

9a

collecting area

9b

discharge area

10

poor

11

output

12

paddle

13

pump

14

wiper member

15

wiper member

16

retaining ring

17

strut

18

stirrer

19

stirrer

20

stirrer

21

stirrer

22

paddle

23

reservoir area

H

upper area

N

level status

P

product

P1

arrow

P2

arrow

P3

arrow

R

rotor axle

S

gap

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2011/131793 A2 [0002]

Claims (14)

Reactor with a heatable housing ( 2 ) whose upper region (H) has a heating surface on the inside ( 3 ) and the inside of a rotor ( 6 ) is interspersed, whose wiper elements ( 4 . 5 . 14 . 15 . 18 ) for distributing a liquid product (P) on the heating surface ( 3 ) are provided, wherein the housing ( 2 ) below the heating surface ( 3 ) a collection area ( 9 . 9a ) and a discharge area ( 9b ) for the product (P), characterized in that the rotor ( 6 ) to the collecting area ( 9 . 9a ) and in the collecting area ( 9 . 9a ) arranged stirring elements ( 8th . 19 - 21 ) for mixing the product (P). Reactor according to claim 1, characterized in that the collecting area ( 9 . 9a ) a discharge area ( 9b ), wherein the rotor extends into the discharge area ( 9b ). Reactor according to claim 1 or 2, characterized in that the rotor ( 6 ) in the longitudinal direction of its rotor axis (R) successively at least two different wiper elements ( 4 . 5 . 14 . 15 . 18 ) owns. Reactor according to claim 3, characterized in that a first wiper element ( 14 . 15 ) as the rotation of the rotor (R) trailing flap is formed, which is a pressing force on the heating surface ( 3 ) exercises. Reactor according to claim 3 or 4, characterized in that a first wiper element ( 4 . 14 . 15 ) in the longitudinal direction of the rotor axis (R) at least one of the first wiper element ( 14 . 15 ) differently configured, further wiper element ( 5 . 18 ), which acts as a fixed wiper element ( 18 ) and a constant distance to the evaporator wall ( 3 ) owns. Reactor according to one of claims 1 to 5, characterized in that the stirring elements ( 8th . 19 - 21 ) are set at an angle which is a displacement of the product (P) transversely to the direction of movement of the stirring elements ( 8th . 19 - 21 ) causes. Reactor according to claim 6, characterized in that a plurality of stirring elements ( 19 . 20 ) are provided with opposing angles to mix the product (P). Reactor according to one of claims 1 to 7, characterized in that the stirring elements ( 8th . 19 - 21 ) for removing product deposits on the housing wall of the collecting area ( 9 . 9a ) are in operative engagement with the housing wall. Reactor according to one of claims 1 to 8, characterized in that the stirring elements are arranged helically. Reactor according to one of claims 1 to 9, characterized in that the collecting area ( 9 ) conically tapering to the upper portion (H) of the housing ( 2 ), wherein the stirring elements ( 8th . 21 ) to the inner contour of the collecting area ( 3 ) are adjusted. Reactor according to one of claims 1 to 10, characterized in that between the upper region (H) of the housing ( 2 ) and the collection area ( 9 . 9a ) a storage area ( 23 ) is arranged as an extension of the upper region (H), in order to increase the residence time of dammed product (P) in the reactor ( 1b ). Reactor according to one of claims 1 to 11, characterized in that the wiper elements ( 4 . 5 . 14 . 15 . 18 ) Have means for recirculating and mixing the product (P). Method for operating a reactor having the features of at least one of claims 1 to 12, characterized in that a residence time of the product within the reactor housing ( 1 . 1a -C) is increased by stowing the product while the rotor ( 6 ) continues to rotate. A method according to claim 13, characterized in that the product is a hydrocarbon-containing product is used, in particular selected from a group comprising waste oil or plastic melt.

Images